The advent of agriculture required early farmers to work the land to their benefit, rather than gather as previously had been done. Early man developed many tools with which to work the soil and provide advantageous conditions for crop development. Over time, many tools have been developed for various purposes. On such purpose is the delivery of water, nutrients and air to the root system of the plant. This is particularly true in modern lawns, where grasses may form a thatch if merely left on the ground after being cut and ground becomes compacted over time. For this purpose, the modern aerator was developed. Aerators began with hand or foot tools that pierced holes in the thatch and ground and have since become mechanized and utilize a plurality of tines to progressively pierce thatch and soil.
Modern aerators, for the most part, have similar concerns. First, holes need to be made with as little disturbance of the surrounding soil as possible. Accordingly, piercings by the tines must be made cleanly and tines must also be extracted cleanly. Second, piercings are ideally made at a depth determined by the operator of the machine. So, depth should be variable. Also, modern lawns in particular present obstacles that must be avoided or, if not avoided, must be worked around by the aerator. This can be particularly difficult to do and to also maintain integrity of surrounding soil as some tines are usually embedded within the soil at times when the aerator needs to be sharply moved to avoid an obstacle.
The present invention is an aerator featuring a tine assembly that is rotatable about an axis parallel to the surface of the ground being treated. As such, tines are easily retracted from the ground if a blocking obstacle is encountered. Also, the rotation of the tine assembly allows for greater flexibility when moving across uneven ground. The aerator also features a biasing system that keeps tines in their most advantageous position in the cycle of piercing and withdrawing from the soil, despite the tilt of the tine assembly.
The present invention represents a departure from the prior art in that the aerator of the present invention allows for a tilting tine assembly to be used in avoiding obstacles, extricating the aerator from obstacles and proceeding over uneven ground surface. Additional features maintain the tines in an advantageous forward position up impact with the ground for use in these objectives.